SELECT 
    DATE(created_at) as reg_date,
    COUNT(user_id) as total_users,
    COUNT(bonus_id) as users_with_bonus,
    ROUND(COUNT(bonus_id) * 100.0 / COUNT(user_id), 2) as percent
FROM users
LEFT JOIN bonuses ON users.user_id = bonuses.user_id
WHERE created_at >= '2024-10-01'
GROUP BY reg_date
ORDER BY reg_date;

SELECT 
    DATE_TRUNC('hour', order_time) as hour,
    COUNT(order_id) as orders,
    SUM(amount) as revenue
FROM orders
WHERE order_time >= CURRENT_DATE - INTERVAL '2 days'
GROUP BY hour
ORDER BY hour;

SELECT 
    product_category,
    COUNT(order_id) as orders
FROM orders
WHERE order_time BETWEEN '2024-10-15 14:00' AND '2024-10-15 15:00'
GROUP BY product_category;

SELECT 
    user_id,
    COUNT(order_id) as order_count,
    SUM(amount) as total_spent
FROM orders
GROUP BY user_id
HAVING COUNT(order_id) >= 10
ORDER BY order_count DESC
LIMIT 20;

UPDATE customers
SET is_vip = TRUE
WHERE customer_id IN (
    SELECT customer_id
    FROM orders
    GROUP BY customer_id
    HAVING SUM(amount) > 1000000
);

def test_discount():
    assert apply_discount(1000) == 1000   # 0% или 10%?
    assert apply_discount(1001) == 900.9  # должно быть 10%
    assert apply_discount(500) == 500     # без скидки

Feature: Скидка на заказ
  Scenario: Сумма ровно 1000
    Given сумма заказа 1000 рублей
    When рассчитывается скидка
    Then скидка не применяется (0%)   # или применяется? Надо решить!

[!@#$%^&*(),.?":{}|<>]

import pytest

def validate_password(password):
    # минимальная проверка для примера
    return any(c in "!@#$%^&*" for c in password)

@pytest.mark.parametrize("pwd,expected", [
    ("pass!", True),      # содержит !
    ("pass", False),      # нет спецсимвола
    ("pass©", False),     # © не в наборе
    ("pass#", True),      # содержит #
])
def test_special_char(pwd, expected):
    assert validate_password(pwd) == expected

# Плохо
if date >= "2025-10-01" and date <= "2025-10-31":
    apply_discount()

# Хорошо — параметры в конфиге или БД
promo = get_promo("october_electronics")
if promo.is_active(date):
    apply_discount()

def test_promo_flexible():
    set_promo_dates("2025-10-01", "2025-10-31")
    assert is_promo_active("2025-10-15") == True
    assert is_promo_active("2025-11-01") == False
    set_promo_dates("2025-10-01", "2025-11-05")
    assert is_promo_active("2025-11-01") == True

def send_order(order, max_retries=3):
    for attempt in range(max_retries):
        try:
            response = requests.post("https://crm/orders", json=order, timeout=5)
            if response.status_code == 200:
                return True
            time.sleep(2 ** attempt)
        except:
            time.sleep(2 ** attempt)
    save_to_dlq(order)  # в отдельную очередь
    return False

key = hashlib.sha256(f"{order_id}_{amount}".encode()).hexdigest()
if redis.exists(key):
    return {"status": "duplicate"}  # уже обработали
redis.setex(key, 86400, "processed")
process_payment(payload)

@pytest.mark.parametrize("date,format,ok", [
    ("15.03.2025", "%d.%m.%Y", True),
    ("2025-03-15", "%Y-%m-%d", True),
])
def test_date_format(date, format, ok):
    assert validate_date(date, format) == ok

async with timeout(2):
    result = await session.get(url)
if timeout:
    return get_cached_data()  # запасной вариант

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